A number of years ago when the refrigeration system in an air conditioner, for example, required repairs or when the refrigerant, such as those sold under the trademark "Freon", was contaminated sufficiently to affect the effectiveness of refrigeration, it was the standard practice to bleed the refrigerant to the atmosphere. This practice was not only costly, but environmentally unsound.
In more recent times it has been the practice to remove the refrigerant with means which confines it while separating contaminants, liquefies it and either returns it to the refrigeration system or stores it. Two such reclaim systems are illustrated in U.S. Pat. Nos. 4,476,688 and 4,646,527. Each includes a compressor, the intake side of which draws the refrigerant from the refrigeration system through contaminant removal means into the compressor and discharges the refrigerant into a condenser which liquefies it and discharges it into storage means from which it may be returned to the refrigeration system, if desired.
Prior art systems of this type have generally not provided truly adequate means for making certain that refrigerant entering the compressor is in a gaseous state, which is necessary to avoid damaging the compressor. Nor do the prior art systems provide means for cooling and controlling the temperature of the liquid refrigerant while it is held or stored in the reclaim system so that the appropriate amount of refrigerant can easily be transferred back to the refrigerator system. Often at the time the refrigeration system of a repaired air conditioner is to be recharged with refrigerant, the gases still within the system are at an elevated temperature resulting in the pressure being high enough that liquid refrigerant at room temperature cannot enter, or can only slowly enter, the system by gravity flow. When refrigerant in the reclaim system has been cooled to a temperature well below the temperature of gases within a container to be charged, the cooler refrigerant will flow partially into the warmer gas, cooling it in the process and thus reducing the pressure of the gas and the resistance to flow of the refrigerant.
It is known in the prior art to provide means for repeatedly recycling the refrigerant through a standard filter-dryer unit during the repair operations, to ensure maximum removal of the acid and water vapor, one such recycling loop being shown in U.S. Pat. No. 4,476,688. Without means to cool the recycling refrigerant, however, its temperature will inevitably rise and this will reduce the efficiency of standard filter-dryers and make it much more difficult to discharge the refrigerant directly from the reclaim system back into the repaired refrigeration system.